Routine maintenance of railroad tracks includes grinding the surface of the rail to remove corrugations to restore a smooth, regular travel surface. Corrugations result from prolonged passage of rail cars over the rails, especially at curves. Corrugations also regularly appear in the vicinity of defective rail joints.
Maintenance of the rails, to remove corrugations, comprises the process of passing a grinding machine, which has longitudinally spaced multiple grinding heads, over each rail. Each grinding machine has a grinding stone attached to a grinding stone holder. The holder is attached to a vertically disposed rotatable drive shaft which is driven by a motor. The grinding head is lowered until the plane surface of the grinding wheel is in contact with the surface of the rail. The head is rotated, creating a grinding motion on the surface of the rail, and the machine is moved along the railroad track to continuously grind lengths of the rail surface as the grinding head passes over it.
The abrasive grinding stones of rail grinding head assemblies are quickly worn down, and must be frequently replaced during on-site operations. Moreover, the grinding wheels are operated at approximately 3600 revolutions per minute, and must transmit sigificant amounts of power to the ground surface. It is also important, due to the high rotational speed of the grinding heads, that the component parts of the grinding head assembly be balanced.
The ideal grinding head assembly would be one that includes an easily accessible attachment means for connecting a disposable grinding stone to the assembly, which is inherently self-centered upon installation, and which is capable of transmitting significant amounts of power to the track rail being ground.